How Is Running Power Different from Cycling Power? (Part 1)

If you’re a triathlete, a bicycle racer, or a fan of either pro sport, you are proba­bly already familiar with the use of power meters in cycling. The power meter transformed training and racing in the cycling world. It has surpassed every other training tool because it delivers an objective and repeatable assessment of overall fitness without any of the drawbacks of previous measurement methods, such as heart rate, speed, and perceived exertion.

In fact, the advan­tages of the cycling power meter are so great—and the margin of error so small in the world of competitive cycling and triathlon—that to ignore the information and the advantage from a power meter would be to concede vic­tory before the race had started.

In the running world, we have recently seen a surge in the popularity of GPS units whose main advances are mapping your route and elevation gain/loss and displaying pace, which is a measure of how long it takes to cover a unit of distance (minutes per mile). The increased adoption of GPS shows that the running world, like the cycling world, is open to embracing technology and its benefits.

While the GPS unit is a useful tool, its contribution to training pales in comparison with the advantages the power meter can provide. The leap in technology is something like the difference between using a typewriter and a computer. In the history of running technology, a stopwatch is probably equivalent to using a typewriter—pretty good at its job, but severely limited in scope. Running’s step up to heart rate monitors was a revelation, but in ret­rospect, it was like moving from the typewriter to what we would now regard as an old, heavy, slow desktop computer. Today’s GPS wrist units are like the first cellphones, much like a flip-phone. The portable power meter for running is the next step, equivalent to the laptop, tablet, and smartphone coming into existence all at once. And while you can still accomplish a lot with a desktop computer, you likely will be much more effective in many ways if you add the laptop, tablet, and smartphone to your arsenal. This is what the power meter brings to the world of training and racing for competitive running.

The leap in technology is something like the difference between using a typewriter and a computer.

In this post, we’ll take a look at two ways cycling and running power meters are different.

#1: Running Power Meters Hitch a Ride on You Instead of the Other Way Around

If you’re familiar with cycling power meters, you know that some measure power from the pedal, some from the crankarm, and others from the rear wheel’s hub. In the past, we even had some that measured from the chain and its tension and speed, while another estimated based on Newton’s Third Law of action-reaction, measuring movement in one direction to estimate another.

The diversity of the types of power meters in the cycling world is likely to be duplicated for running; as more running power meters come on the mar­ket, the way they estimate, measure, or calculate power will change, creating a variety of types of products.

The current power meters for running use sensors at the chest or core of the body, or through sensors at the shoe, such as an insole. I believe we will soon see foot pods as a way to measure power, and perhaps in the years to come we will see other types of sensors we can’t even imagine yet, as cadence is quite simple to measure through the foot, leg, hand, or even through the rotation of the body. All a product has to do is find a way to measure the force or estimate it based on other forces.

#2: Running Power Meters Can Measure 2 or 3 Dimensions Instead of Just 1

Cycling power meters were developed to measure the work rate, the power actually applied to the pedals to move the bike forward. Note that this does not mean the cyclist’s body isn’t doing any other work on a bike; it means that the bike’s power meter can measure only the work that is applied specifically to it. In some ways, this makes the job of going faster easy: Pro­duce more watts and you’re a faster cyclist.

In some ways, this method of measurement reveals a limitation of the technology for cycling. If I hop on a bicycle that doesn’t fit me, and I don’t have the seat height right, or I am leaning too far forward or back on the seat, the power meter on the bike cannot tell me that I am not in a good position. It can’t tell me how much power I am wasting, nor that I could get more watts with a better posi­tion. It can only give me the numbers that I apply to the bike’s drivetrain. This is what makes a power meter on the bike a great and simple tool. Raise the watts, and you know you’re doing better.

Competitive cyclists could certainly learn a lot about themselves if they could see how efficiently they produce those watts. They might find flaws in their pedaling technique or discover that they have a poor bike position. But a cycling power meter cannot measure any expenditures of energy that the rider might be wasting through extraneous body movements; it can only report how much power is flowing from the pedals through the drivetrain.

Fortunately, that’s not the case with our running power meters, and it’s one of the huge advantages this tool provides.

Power meters for run­ning are much more complex than for cycling because we are dealing with three planes of movement in running instead of just one in cycling. Running power meters show the power data for factors that do help me, along with the data for factors that do not help me. We have productive work (horizontal mostly) that we are measuring, and unproductive work (vertical and lateral) that we are also measuring.

And though it is more complex, this extra data is also what makes a power meter for running an incredible tool compared with a bicycle power meter, because it lets me see where I am potentially inefficient in my running technique. Power produced in directions or planes that don’t help me is power wasted, and the running meter can help me reduce that wasted work. So the limitation of the data in a bike power meter is a disadvantage, while the abundance of data in the running power meter is a big advantage.

RUN WITH POWER is the groundbreaking guide you need to tap the true potential of your running power meter like SHFT, Stryd, or RPM2. From 5K to ultramarathon, a power meter can make you faster—but only if you know how to use it. Just viewing your numbers is not enough; you can only become a faster, stronger, more efficient runner when you know what your key numbers mean for your workouts, races, and your season-long training. In Run with Power, TrainingBible coach Jim Vance offers the comprehensive guide you need to find the speed you want.